JP5241210B2 - Seismic isolation structure plug composition, seismic isolation structure plug and seismic isolation structure - Google Patents

Description

  The present invention relates to a plug composition for a base isolation structure, a plug for a base isolation structure using the composition, and a base isolation structure using the plug, and in particular, sufficient damping performance and displacement followability. In addition, the present invention relates to a plug composition for a seismic isolation structure capable of providing a plug having excellent repeatability.

  2. Description of the Related Art Conventionally, seismic isolation structures in which soft plates having viscoelastic properties such as rubber and hard plates such as steel plates are alternately stacked have been used as bearings for seismic isolation devices. Among such seismic isolation structures, for example, there is a structure in which a hollow portion is formed at the center of a laminated body made of a soft plate and a hard plate, and a plug is press-fitted into the hollow portion.

  As the plug, a plug made entirely of lead is often used, and when the laminated body undergoes shear deformation, the plug is plastically deformed to absorb vibration energy. However, lead has a large environmental load and a high cost for disposal. For this reason, an attempt has been made to develop a plug having sufficient damping performance, displacement followability, etc., using a lead substitute material.

  For example, Japanese Patent Laid-Open No. 2006-170233 employs a tin plug or a tin alloy plug in place of a lead plug, and a seismic isolation that specifies a ratio between the outer diameter of the plug and the outer diameter of the laminate within a specific range. A structure has been proposed, and according to the base isolation structure, an excellent base isolation effect can be obtained.

JP 2006-170233 A

  However, as a result of studies by the present inventors, it has been found that the seismic isolation structure using a tin plug or a tin alloy plug does not have sufficient repetitive stability, and there is room for improvement in terms of performance.

  In view of the above, an object of the present invention is to solve the problems of the prior art described above, and to provide a seismic isolation structure plug capable of providing sufficient damping performance, displacement followability, and excellent repeatability. The object is to provide a plug composition for a seismic structure. Another object of the present invention is to provide a plug for a base isolation structure using the composition and a base isolation structure using the plug.

  As a result of intensive studies to achieve the above object, the present inventor has obtained sufficient damping performance and displacement followability by using a composition containing soft metal powder and iron powder for a plug of a seismic isolation structure. In addition, the inventors have found that a seismic isolation structure having excellent repetitive stability can be obtained, and the present invention has been completed.

That is, the plug composition of the seismic isolation structure according to the present invention contains soft metal powder and iron powder, and the content of the iron powder is 50 to 74% by volume . Here, the soft metal refers to a metal that is easily deformable and rich in spreadability, and refers to gold, silver, copper, tin, lead, alloys thereof, and the like.

Oite plug composition of the present invention, the content of the iron powder is 50 to 74 vol%. Thereby, since the friction between the iron powders at the time of deformation is sufficiently large, a sufficient damping effect can be obtained, and durability is sufficiently ensured.

  In the plug composition of the present invention, the soft metal powder is preferably tin powder or tin alloy powder.

  The plug for a seismic isolation structure of the present invention is manufactured from the above plug composition, and the seismic isolation structure of the present invention includes a rigid plate having rigidity and an elastic plate having elasticity. And a plug having a hollow portion extending in the stacking direction, and a plug press-fitted into the hollow portion of the stack, and the plug is the plug for the seismic isolation structure. It is characterized by.

According to the present invention, it contains soft metal powder and iron powder, the content of the iron powder is 50 to 74% by volume, has sufficient damping performance, displacement followability, and excellent repeat stability. It is possible to provide a plug composition for a seismic isolation structure capable of producing a seismic isolation structure plug. Moreover, it is possible to provide a seismic isolation structure plug using such a composition and having sufficient damping performance, displacement followability, and excellent repeatability, and a seismic isolation structure using the plug. .

<Composition for plug>
Below, the composition for plugs of this invention is demonstrated in detail. The composition for a plug of the seismic isolation structure according to the present invention contains soft metal powder and iron powder, the content of the iron powder is 50 to 74% by volume , and if necessary, Other components may be contained.

  The inventor examined a tin plug as an alternative to a lead plug, but it was found that the seismic isolation structure using the tin plug has room for improvement in repeated stability. Therefore, further investigation was carried out, and plugs were produced from various metal powders by compression molding, and the plugs were used for seismic isolation structures, but in most cases, the metal powders were rubbed and cracked, resulting in sufficient durability. Plugs having the same properties could not be obtained, and there were problems with repeated stability. However, by selecting soft metal powder and iron powder from such metal powder, and making plugs from the mixed metal powder, it has sufficient durability, damping characteristics, displacement followability, etc., and is stable repeatedly The present inventors have found that a plug for a seismic isolation structure having excellent performance and performance equivalent to or higher than that of a lead plug can be obtained and the present invention has been conceived. If a plug composition containing no soft metal powder is used, the moldability is poor and the iron powder is rubbed and cracked, so that a plug having sufficient durability cannot be obtained. If a plug composition that does not contain it is used, the repeated stability is insufficient.

  The soft metal powder used for the plug composition of the present invention acts as a binder and has an effect of preventing the iron powder from rubbing and cracking and improving the durability of the plug. Since the soft metal powder is easily plastically deformed by the load at the time of deformation of the plug, the displacement followability of the plug can be improved.

  As the soft metal powder used for the plug composition of the present invention, in addition to tin (Sn) powder, Sn-Zn, Sn-Cu-Ni, Sn-Ag-Cu, Sn-Ag, Sn-Bi, Sn-Ag Powders of tin alloys such as -Cu-Bi, Sn-Ag-In-Bi, and Sn-Sb can be used. These soft metal powders may be used alone or in a combination of two or more. Moreover, it is preferable that melting | fusing point is 75-500 degreeC from a viewpoint of molding processability for the soft metal powder to be used.

  In the plug composition of the present invention, the content of the soft metal powder is preferably in the range of 26 to 50% by volume. When the content of the soft metal powder in the composition for plugs is less than 26% by volume, the contact between the iron powders increases, and the repeated durability decreases. On the other hand, when the content of the soft metal powder in the plug composition exceeds 50% by volume, the ratio of the iron powder decreases, the distance between the iron powders becomes too wide, and the friction between the iron powders during deformation is reduced. Since it becomes small, attenuation performance is insufficient.

  Since the soft metal powder is deformed when the plug composition is molded into a plug, its shape is not particularly limited. From the viewpoint of handleability and availability, the soft metal powder preferably has a particle size in the range of 1 μm to 10 mm. Moreover, it does not need to be in the state of metal powder, and it can be liquefied and mixed with iron powder even if it is in the form of a lump.

  On the other hand, the iron powder used in the plug composition of the present invention is a material mainly responsible for the damping performance of the plug. Specifically, the vibration is attenuated by friction between the iron powders and friction between the iron powder and the soft metal. . In addition, when the composition for plugs does not contain iron powder, the damping performance of a plug falls significantly and sufficient damping performance, displacement followability, etc. cannot be obtained.

  The iron powder used in the plug composition of the present invention is inexpensive and has a high breaking strength compared to other metal powders, and the plug for a seismic isolation structure mainly composed of iron powder is too hard. It is neither too fragile nor too fragile, so that excellent damping performance can be exhibited over a long period of time. In addition, the iron powder to be used may be partially oxidized. Examples of the iron powder include reduced iron powder, electrolytic iron powder, sprayed iron powder, pure iron powder, and cast iron powder. Among these, reduced iron powder is preferable.

In the plug composition of the present invention, the iron powder content is in the range of 50 to 74% by volume. When the content of the iron powder in the plug composition is less than 50% by volume, the distance between the iron powders is too wide, and the friction between the iron powders during deformation becomes small, so that the damping performance is insufficient. On the other hand, if the content of iron powder in the plug composition exceeds 74% by volume, the contact between the iron powders increases and the durability decreases repeatedly, and when the plug is formed from the plug composition, It is difficult to sufficiently remove air from the composition for use, and the volume of the plug becomes significantly larger than the ideal volume (the volume in the case where no air is mixed), so that the damping performance of the plug is lowered.

  The particle size of the iron powder is preferably in the range of 0.1 μm to 2 mm, and more preferably in the range of 1 μm to 150 μm. When the particle size of the iron powder is less than 0.1 μm, handling is difficult. On the other hand, when the particle size of the iron powder exceeds 2 mm, the friction between the iron particles tends to decrease and the damping effect tends to decrease. If the particle size of the iron powder is 1 μm or more, handling is easy, and if the particle size of the iron powder is 150 μm or less, the damping performance of the plug is sufficiently high.

  The shape of the iron powder is preferably indefinite. Here, the indefinite shape means that not only one type of shape such as a spherical shape but also shapes having various forms such as those having irregularities and protrusions are mixed. The shape of the iron powder obtained by pulverizing the bulk is naturally indefinite, but compared with the case of using spherical iron powder, the use of amorphous iron powder provides better damping effect. It was. This is because, when using irregular shaped iron powder, a frictional effect occurs between the iron powders and between the iron powder and the soft metal. This is considered to be due to the fact that the attenuation performance is improved.

  The composition for plugs of the present invention is not particularly limited except that soft metal powder and iron powder are used, and can be produced, for example, by mixing iron powder and soft metal powder using a known mixer.

<Seismic isolation structure plug>
The plug for a seismic isolation structure of the present invention is characterized by being manufactured from the above-described plug composition, has sufficient damping performance and displacement followability, and is excellent in repeated stability. In addition, the plug for seismic isolation structure of this invention can be manufactured as follows (1) or (2) using the said composition for plugs, for example.

(1) The plug composition prepared as described above is taken out of the mixer, transferred to a molding apparatus, and pressed into a plug by applying pressure. As a press machine used in this step, a machine that is usually used in the technical field can be adopted. Further, the press working conditions are not particularly limited, and conditions suitable for molding of the plug can be set by appropriately modifying the conditions normally used in the technical field. For example, as the conditions for pressing, the pressing temperature is preferably in the range of room temperature to 150 ° C., and the molding pressure is preferably 0.7 t / cm ² or more.

  (2) The plug composition prepared as described above is taken out of the mixer, transferred to a mold, and heated to a temperature not lower than the melting temperature of the soft metal powder and lower than the melting temperature of the iron powder to be molded. But plugs can be made.

<Seismic isolation structure>
The seismic isolation structure of the present invention includes a laminate having a rigid plate having rigidity and an elastic plate having elasticity stacked alternately, and having a hollow portion extending in the lamination direction, and press-fitting into the hollow portion of the laminate. The plug is a plug for the above-described seismic isolation structure, and has high damping performance and displacement followability, and is excellent in repeated stability. Below, the seismic isolation structure of this invention is demonstrated in detail, referring a figure.

  A seismic isolation structure 1 shown in FIG. 1 is formed by alternately laminating rigid plates 2 having rigidity and elastic plates 3 having elasticity, and has a cylindrical hollow portion extending in the laminating direction (vertical direction) as a central portion. The laminate 4, the plug 5 press-fitted into the hollow portion of the laminate 4, and the flange 4 fixed to both ends (upper and lower ends) of the laminate 4 and the plug 5. The outer peripheral surface is covered with a covering material 7.

  The rigid plate 2 and the elastic plate 3 constituting the laminated body 4 are firmly bonded by, for example, vulcanization adhesion or an adhesive. In the vulcanization adhesion, the rigid plate 2 and the unvulcanized rubber composition are laminated and then vulcanized, and the vulcanized product of the unvulcanized rubber composition becomes the elastic plate 3. Here, as the rigid plate 2, a metal plate such as a steel plate, a ceramic plate, a reinforced plastic plate such as FRP, or the like can be used. On the other hand, as the elastic plate 3, a vulcanized rubber plate or the like can be used. Moreover, the laminated body which comprises the seismic isolation structure of this invention does not need to be covered with the coating | covering material 7, but when the outer peripheral surface of the laminated body 4 is covered with the coating | covering material 7, the laminated body 4 Rain and light do not reach from the outside, and deterioration of the laminate 4 due to oxygen, ozone, and ultraviolet rays can be prevented. As the covering material 7, the same material as the elastic plate 3, for example, vulcanized rubber can be used.

  When the laminated body 4 receives a shearing force in the horizontal direction due to vibration, the laminated body 4 undergoes shear deformation and absorbs vibration energy. Further, since the laminate 4 is formed by alternately laminating the rigid plates 2 and the elastic plates 3, the compression is suppressed even when a load is applied in the lamination direction (vertical direction).

  In the seismic isolation structure 1, the plug 5 is press-fitted into the hollow part of the laminated body 4, and when the horizontal shearing force is received by vibration, the plug 5 is sheared and deformed together with the laminated body 4. The energy can be effectively absorbed, and the vibration can be quickly damped. Here, since the plug manufactured from the composition containing soft metal powder and iron powder is used as the plug 5, the seismic isolation structure of the present invention has sufficient damping performance and displacement followability. Excellent repeatability.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to the following examples.

(Examples 1-3)
Using a mixer, iron powder and tin powder or tin alloy powder were mixed in the formulation shown in Table 1 to prepare a plug composition. Next, the plug composition was pressed at a temperature of 100 ° C. and a pressure of 1.3 ton / cm ² to produce a columnar seismic isolation structure plug having a diameter of 45 mm.

(Comparative Example 1)
Using a mixer, iron powder and aluminum powder were mixed to prepare a plug composition. Next, the plug composition was pressed in the same manner as in Examples 1 to 3 to produce a plug for a seismic isolation structure.

(Comparative Example 2)
The iron powder was pressed in the same manner as in Examples 1 to 3 to produce a plug for a seismic isolation structure.

(Comparative Examples 3 and 4)
Aluminum or iron cylinders were prepared as plugs for seismic isolation structures.

<Evaluation>
Cylindrical hollow part in the center, outer diameter is 225 mm, rigid rigid plate [iron plate] and elastic elastic plate [vulcanized rubber (G '= 0.4 MPa)] are laminated alternately The above seismic isolation structure plug was press-fitted into the hollow portion of the laminated body, thereby producing the seismic isolation structure having the structure shown in FIG. The volume of the plug was 1.01 times the volume of the hollow part of the laminate. With respect to the above-mentioned plug for seismic isolation structure, the damping performance, followability, repeatability and moldability were evaluated by the following methods. The results are shown in Table 1.

(Attenuation performance)
The seismic isolation structure was subjected to a horizontal deformation with a reference surface pressure applied in the vertical direction using a dynamic testing machine to cause shear deformation with a specified displacement. The vibration displacement was set such that the total thickness of the laminate was 100%, the strain was 50 to 250%, the vibration frequency was 0.33 Hz, and the vertical surface pressure was 10 MPa. FIG. 2 shows the relationship between the horizontal deformation displacement (δ) and the horizontal load (Q) of the seismic isolation structure. As the area ΔW of the region surrounded by the hysteresis curve in FIG. 2 becomes wider, it means that more vibration energy can be absorbed. Here, for the sake of simplicity, the damping performance of the plug was evaluated based on an intercept load Q _{d at} a strain of 200% (a horizontal load value at a displacement of 0). The intercept load Q _d is expressed by the following formula using the loads Q _d1 and Q _d2 at the point where the hysteresis curve intersects the vertical axis:
Q _d = (Q _d1 + Q _d2 ) / 2
Calculated from As Q _d increases, the area of the region surrounded by the hysteresis curve increases, indicating that the attenuation performance is excellent.

(Followability)
When the laminate was subjected to shear deformation, it was evaluated whether or not the plug could follow the deformation. A case where the plug could follow the deformation was evaluated as ◯ (good), and a case where the plug could not be followed was evaluated as x (bad).

(Repetitive stability)
As a preliminary test, shear deformation was performed for each of three cycles of 50%, 100%, 150%, 200%, and 250% strain. Next, when shear deformation was applied in the order of 100% strain (1), 200% strain, and 100% strain (2) for 3 cycles each, Q _d (third cycle of 100% strain (2)) / Q _d A case where (the third cycle of 100% strain (1)) was 0.5 or more was evaluated as ◯ (good), and a case where it was less than 0.5 was evaluated as x (defective).

(Molding processability)
The workability at the time of producing a plug for a base-isolated structure by pressing the plug composition was evaluated. The case where the workability was good was evaluated as ○, and the case where the workability was poor was evaluated as ×.

* 1 Iron powder, particle size = 40μm, irregular reduced iron powder
* 2 Tin powder, melting point = 449 ℃, particle size = 40μm
* 3 Tin alloy powder A, Sn—Zn, Sn = 92 mass%, Zn = 8 mass%, melting point = 199 ° C., particle size = 40 μm
* 4 Tin alloy powder B, Sn-Ag-Cu, Sn = 96.5 mass%, Cu = 0.5 mass%, Ag = 3 mass%, melting point = 218 ° C., particle size = 40 μm
* 5 Aluminum powder, melting point = 660 ℃

  From Examples 1 to 3 in Table 1, by using a plug prepared from a plug composition containing soft metal powder and iron powder, the damping performance of the seismic isolation structure can be sufficiently secured, and displacement followability It can be seen that the repetition stability and molding processability are also good.

  On the other hand, it can be seen from Comparative Example 1 that the plug composition containing non-soft metal powder and iron powder has poor moldability.

  Further, it can be seen from Comparative Example 2 that when a plug made only from iron powder is used, the repeated stability and the moldability are poor. This is thought to be because the iron powders rub against each other and break. Therefore, it can be seen from this result that a soft metal needs to be interposed between the iron powders.

  Further, it can be seen from Comparative Examples 3 and 4 that when an aluminum or iron cylinder is used as the plug, the followability and repeatability are poor.

It is sectional drawing of an example of the seismic isolation structure of this invention. It is a graph which shows the relationship between horizontal deformation displacement (delta) and horizontal direction load (Q) in the seismic isolation structure using a plug.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Seismic isolation structure 2 Rigid board 3 Elastic board 4 Laminated body 5 Plug 6 Flange board 7 Coating | covering material

Claims (4)

A composition for a plug of a seismic isolation structure , comprising soft metal powder and iron powder , wherein the content of the iron powder is 50 to 74% by volume .   The composition for a plug of a seismic isolation structure according to claim 1, wherein the soft metal powder is tin powder or tin alloy powder. The composition for plugs of the seismic isolation structure according to claim 1 or 2 is pressed by applying pressure with a molding apparatus, or more than a melting temperature of the soft metal powder and a mold of the iron powder. A plug for a base-isolated structure manufactured by heating and molding to a temperature below the melting temperature . A seismic isolation system comprising a laminate having a hollow portion extending in the lamination direction, and a plug press-fitted into the hollow portion of the laminate, wherein a rigid plate having rigidity and an elastic plate having elasticity are alternately laminated. In the structure,
The said plug is a plug for seismic isolation structures of Claim 3. The seismic isolation structure characterized by the above-mentioned.

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